Gas recovery method and apparatus

ABSTRACT

A method of reclaiming the gas used for the dispensing of liquids from a container or to assist in enabling liquids to be dispensed and thereby enable the gas to be re-used. The apparatus for carrying out the above method including a gas compressor and container means for connection thereto, another container from which liquid is to be dispensed, and at least one gas cylinder, means for connecting an empty container to the gas container and compressor to enable gas from the empty container to be pumped to the gas container and pressure regulating means to insure that pressurization of the gas container cannot take place.

United States Patent 11 1 Cole 1451 July 10, 1973 GAS RECOVERY METHOD AND 2,212,379 8/1940 Smith 141/66 APPARATUS 706,792 8/1902 August 222/399 X Inventor: Samuel Peter Cole, v Pasture Gate, England 94,612 10/1897 Germany 141/37 [73] Assignee: J. W. Lees & Company (Brewers) Limited Middleton and the Lake of Primary ExammerHouston S. Bell, .lr. Mann, England Attorney-James E. Nllles PP N05 138,092 A method of reclaiming the gas used for the dispensing of liquids from a container or to assist in enabling liq- 30] Foreign Application priority Data u1ds to be d1spensed and thereby enable the gas to be re-used. The apparatus for carrying out the above Apr. 29, 1970 Great Britain ..20511/70 method includinga gas compressor and Container means for connection thereto, another container from [52] US. Cl .1 141/4, 141/52, 141/65 which liquid is to be dispensed and atleast one gas [51] Int. Cl B65b 1/04, B65b 3/04 inder, means for connecting an empty container to the [58] Field of2Search 62/474, 137/ 12.5, gas container and compressor to enable gas from the 137/ 09, 141/1 4 f, empty container to be pumped to the gas container and 222/ 17/16 53/79 96 pressure regulating means to insure that pressurization l References Cited of the gas contamer cannot take p ace UNITED STATES PATENTS 11 Clams, 1 Drawmg 2,149,633 3/1939 Schnoor 222/399 X 3,626,970 12/1971 Jones et al 2,295,539

9/1942 Beach 222/399 UX PATENIEDJUL 1 mm 3.744.537

INVENTOR: S. 'P. c: 01.5

1 GAS RECOVERY METHOD AND APPARATUS This invention concerns a method of recovering of gas and is particularly though not exclusively concerned with the recovery of the gas used to dispense beer, lager and like alcoholic beverages (hereinafter simply referred to as beer) and non-alcoholic beverages from storage containers. The invention may also be applied to the recovery of gas from containers which have contained liquids, other than consumables, which require dispensing from time to time.

it is well known that the so called keg beers may be removed from their containers by introducing into the container, as required, a gas such as carbon dioxide which, when the valve at a dispensing station is opened, causes the beer to pass through a dispensing head. Such a system is referred to as a full pressure" system and is probably not so widely used as the so-called top pressure system in which the gas is used at a lower pressure to maintain the beer in consistent condition whilst the physical work done to raise the beer to the dispensing head is accomplished using, for example, an electric pump.

At present the hotelier, publican or the like purchases containers of gas under high pressure and uses the gas from such containers until the supply is exhausted whereupon he connects a new container of gas to his beer container. It will be appreciated that, as a beer container is emptied of beer it becomes full of gas and this gas must be vented to atmosphere before the container can be re-filled with beer. It will also be appreciated that, not only is this procedure wasteful, since the gas is completely lost, but that it is also potentially dangerous since if the person who is employed by a brewer to re-fill the beer container is not careful when he receives the containers for re-filling, he may inadvertently attempt to open the container before the gas is removed whereupon the pressure of gas therein can cause the filler cap to be blown off the container with considerable force.

With the growing popularity of keg beers the need for gas is increasing at a comparatively high rate and thus the hoteliers or publicans costs are increasing due to the increasing rate of usage of gas.

It should be appreciated that there are other instances where gas is used for causing the removal of liquids from containers and therefore whilst in this specification reference is made to the use of gas for the dispensing of beer, this is not to be considered as a restriction of the invention.

It is the object of the present invention to provide a method of reclaimingthe gas used for the dispensing of liquids from container or to assist in enabling liquids to be dispensed and thereby enable the gas to be re-used. Consequent upon this invention it follows that the risk of of accidents in the establishment which re-fills containers with liquid for dispensing is substantially reduced if not completely eliminated.

According to the present invention the method of recovering 'a gas from a container or series of containers comprises the steps of attaching to a first container, when it contains only the gas used during the dispensing of a liquid therefrom, of a gas recovery line, pumping gas from the first container into a receiving container until a pre-determined pressure exists in the container being evacuated and repeating, if necessary, the evacuation step on a further container or containers to be evacuated, until a pre-determined pressure exists in the receiving container and discontinuing the pumping, the gas then being ready for re-use during dispensing liquids from a container or containers to be emptied.

According to one specific aspect of the present invention the method of recovering the gas is applied to the recovery of the gas used during the emptying of a beer container or series of such'containers and includes the steps of filtering the gas during recovery to maintain its purity whereby it can be re-used during dispensing beer from a further beer container or containers.

The invention will now be described further, by way of example only, with reference to the method of recovery of gas from beer containers and the method by which such recovered gas is re-used. It will be assumed that the gas will be used in a top pressure system.

The accompanying drawing illustrates diagrammatically, and by way of example only, one form of apparatus which can be used to carry the invention into effect.

Initially the user will have a gas cylinder 10 of carbon dioxide gas attached to the container 11, or-containers, from which his beer is to be dispensed. In the gas line 12 from the cylinder 10 to the or each container ll there is a pressure gauge 13 and of course each beer container 11 is connected, via a line 14, a pump or beer engine 15 to a dispensing head 16 at the bar. The connection of the gas line 12 and the beer line 14 to the, or each container 11 is of known form. Additionally there is provided a compressor 17 having a gas container 18 attached thereto. The compressor 17 is provided with a filtering means 19 by which gas drawn from a container 11 can be filtered before it enters the gas container 18 and additionally cut out switches are provided, the first one of these switches 20 is set to ensure that the gas pressure within the gas container 18 cannot exceed a pre-determined value and the second 21 (which incorporates a pressure guage 21a) is set to ensure that beer containers 11 cannot be evacuated to below a pre-determined pressure. For example, the first switch may be set to cut out a compressor motor 22 at a container pressure of say 120 p.s.i.q. and the second switch 21 may be set to ensure that the compressor motor 22 will cut out at a beer container gas pressure of say 2 p.s.i.q. The second switch 21 in any event is set to cut out the motor 22 of the compressor 17 at a beer container pressure such that it is substantially certain that no air can be pumped into the gas container 18; this is necessary to avoid the possibility of contamination of the carbon dioxide with air or other gas to prevent contamination of beer when gas from the gas container 18 is being re-used.

The first switch 20 is clearly set to operate at such a gas container pressure as will ensure that there is no risk of pressurising the gas container 18 to such a pressure as will result in the danger of explosion existing.

Now assume that the gas from the gas cylinder 10 has been exhausted after being used say to empty four beer containers 11. These containers now contain substantially only carbon dioxide gas, with some beer vapour therein. Each empty (in so far as beer is concerned) container 11 is in turn disconnected, from the gas supply line 12 and the beer line 14 and in placeof this there is connected a line to the compressor. For convenience an empty container is shown connected via a line 23 to the compressor 18. The motor 22 is switched on and the containers 11a are in turn evacuated to 2 p.s.i.g. whereupon they are ready to be returned to the brewery for re-filling. Whilst the evacuation is taking place it is possible either to use gas from the gas container 18 of the compressor 17 for use whilst other beer containers 11 are being emptied of beer, or of course initially a second gas cylinder a (shown in chain line) may be connected to the beer containers 11. In this latter case it is possible to connect the second gas cylinder 10a into a supply line 24 from the gas container 18 so that if the pressure within the container 18 is below a pre-determined level gas will automatically be supplied from the cylinder 10a until such time as the gas pressure in the container 18 is high enough to ensure correct operation. It will be appreciated that the container 18 may require the gas from more than say four beer containers 11 before it is pressurised to a sufficient extent to enable it to be used to supply gas to a beer container or containers 11 from which beer is being dispensed. In any event, as a precautionary measure there should be a spare gas cylinder for use in the beer cellar.

When the gas container 18 of the compressor 17 has been filled to the pre-determined pressure the carbon dioxide therein can be used to maintain top pressure in the beer containers 11 until the container 18 is either partially exhausted, when it can be further filled with gas from an empty beer container 110, or wholly exhausted. In any event, it is possible to ascertain the pressure of gas in the container 18 by reading a pressure gauge 25.

It will be appreciated that each time an empty beer container 11a is connected to the compressor 17 and each time a full beer container 11 is connected to the compressor 17 or to a spare gas cylinder 10a there will be a small loss of gas but the loss is nominal if care is taken in making or breaking gas line connections to the beer containers 11 or 11a so that the need for obtaining gas from a supplier is substantially reduced, thus reducing overheads in so far as the hotelier or publican is concerned. The recovered gas can be used and rerecovered many times.

In order to ensure that the gas container 18 of the compressor 17 is initially free from air it would be convenient for it to be evacuated and filled with carbon dioxide before being delivered or used by the hotelier or publican. Additionally as a further safeguard against the contamination of the carbon dioxide, a purity detector 26 could be provided on the outlet line 24 from the gas container 18, such detector being, for example, in the form of a solenoid valve which would be effective to cut ofi the delivery of gas in the event of air or other contaminant being present in the gas container 18.

As shown in the drawing th gas container 18 is provided with a drain cock 27 so that any liquid in the container can be removed periodically, or in fact gas can be allowed to escape if it has become contaminated. Additionally in the gas supply line 24 there is provided a stop cock 28 in order that the gas container .18 can be isolated from the beer container or containers 11 and a gas cylinder 10.

In a further modification it is possible to include, in the gas line 23 from the container 11a, a gas drying unit. As a matter of practicability this dryer is conveniently incorporated with a filter (as indicated by the reference numeral 29),

The gas recovery unit, that is the apparatus contained within the broken line 30, is conveniently rendered portable by, for example, mounting it on a wheeled base.

If desired the gas container 18 referred to above may be replaced by a smaller gas container, which is connectable to the compressor 17 by preferably means of a quick release fastening device. Such a condition is envisaged to cater for the need, in some cases, to have a simple means for recovering the gas from used containers 11 which are at widely spaced positions. This atrangement makes it possible to have one compressor unit at a central point and to bring the empty containers 11 to that point to charge the small gas containers so that they can then be delivered to the various locations at which they are required. In such cases there would be provided a filter at each of the points at which a small gas container is to be used.

I claim 1. The method of recovering a gas from a used gas container comprising the steps of attaching a gas recovery line to a used gas container which contains only the gas used during the dispensing of a liquid therefrom, pumping gas from the used gas container into a receiving container until a predetermined low but positive pressure exists in the used gas container being evacuated and repeating, if necessary, the evacuation step on a further container to be evacuated, until a low but positive pressure exists in said further container until a predetermined positive pressure exists in the receiving container and discontinuing the pumping, the gas in the receiving container then being ready for re-use during dispensing of liquids from another container to be emptied.

2. The method as claimed in claim 1 when applied to the recovery of the gas used during the emptying of a beer container and includes the steps of filtering the gas during recovery to maintain its purity whereby it can be re-used during dispensing beer from a further beer container.

3. Apparatus for recovering gas from a container comprising a first gas container and compressor, means for connecting thereto a container from which liquid is to be dispensed and at least one gas cylinder, means for connecting a used gas container to said first gas container and to the compressor to enable gas from the used gas container to be pumped to the first gas container, pressure regulating means in the form of a first switch to insure that over-pressurization of the first gas container cannot take place, and switch means between said used gas container and said first gas container, and said first gas container to insure that evacuation of said used gas container is discontinued when a small but positive pressure exists therein.

4. Apparatusv as claimed in claim 3 in which the means for connecting the first gas container to the used gas container includes a gas filtration element and a pressure regulating valve.

5; Apparatus as claimed in claim 3 in which the first gas'container is provided with a first pressure switch and pressure gauge, said first pressure switch being operative to cut out a compressor motor at a predetermined gas pressure within the first container.

to at least one beer container.

10. Apparatus as claimed in claim 3 in which a gas dryer is provided between the first gas container and the used gas container.

11. Apparatus as claimed in claim 3 in which a wheeled base is provided to render the apparatus portable. 

1. The method of recovering a gas from a used gas container comprising the steps of attaching a gas recovery line to a used gas container which contains only the gas used during the dispensing of a liquid therefrom, pumping gas from the used gas container into a receiving container until a predetermined low but positive pressure exists in the used gas container being evacuated and repeating, if necessary, the evacuation step on a further container to be evacuated, until a low but positive pressure exists in said further container until a predetermined positive pressure exists in the receiving container and discontinuing the pumping, the gas in the receiving container then being ready for re-use during dispensing of liquids from another container to be emptied.
 2. The method as claimed in claim 1 when applied to the recovery of the gas used during the emptying of a beer container and includes the steps of filtering the gas during recovery to maintain its purity whereby it can be re-used during dispensing beer from a further beer container.
 3. Apparatus for recovering gas from a container comprising a first gas container and compressor, means for connecting thereto a container from which liquid is to be dispensed and at least one gas cylinder, means for connecting a used gas container to said first gas container and to the compressor to enable gas from the used gas container to be pumped to the first gas container, pressure regulating means in the form of a first switch to insure that over-pressurization of the first gas container cannot take place, and switch means between said used gas container and said first gas container, and said first gas container to insure that evacuation of said used gas container is discontinued when a small but positive pressure exists therein.
 4. Apparatus as claimed in claim 3 in which the means for connecting the first gas container to the used gas container includes a gas filtration element and a pressure regulating valve.
 5. Apparatus as claimed in claim 3 in which the first gas container is provided with a first pressure switch and pressure gauge, said first pressure switch being operative to cut out a compressor motor at a predetermined gas pressure within the first container.
 6. Apparatus as claimed in claim 3 in which there is provided, between the first gas container and the used gas container, a second pressure switch and pressure gauge, said second pressure switch being operative to cut out a compressor motor when the gas pressure in the used gas container reaches a pre-determined value.
 7. Apparatus as claimed in claim 3 in which a gas filtration element is provided between the used gas container and the first gas container.
 8. Apparatus as claimed in Claim 3 in which a drain cock is provided in the first gas container, and in which a stop cock is provided between the first gas container and the used gas container.
 9. Apparatus as claimed in claim 3 in which the first gas container serves to receive and supply gas from and to at least one beer container.
 10. Apparatus as claimed in claim 3 in which a gas dryer is provided between the first gas container and the used gas container.
 11. Apparatus as claimed in claim 3 in which a wheeled base is provided to render the apparatus portable. 